Joseph H. Crabb

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The infectivity of three Cryptosporidium parvum isolates (Iowa [calf], UCP [calf], and TAMU [horse]) of the C genotype was investigated in healthy adults. After exposure, volunteers recorded the number and form of stools passed and symptoms experienced. Oocyst excretion was assessed by immunofluorescence. The ID50 differed among isolates: Iowa, 87 (SE, 19;(More)
Cryptosporidium parvum causes acute diarrhea in immunocompetent individuals and a severe life-threatening disease in immunocompromised individuals, including AIDs patients. No efficacious therapy for cryptosporidiosis has yet been reported. However, treatment of some patients with cryptosporidiosis with hyperimmune bovine colostrum has ameliorated or(More)
Enterotoxigenic Escherichia coli (ETEC) is the most commonly isolated pathogen responsible for travelers' diarrhea and the cause of up to 650 million cases of pediatric diarrhea per year in the developing world. As a safe alternative to the prophylactic use of antibiotics, a hyperimmune bovine milk antibody product with specific activity against purified(More)
Cryptosporidium parvum, a zoonotic Apicomplexan pathogen, causes profound diarrhea, malnutrition, and dehydration in patients with AIDS. A less severe, self-limited disease occurs in immunocompetent individuals, particularly children, animal handlers, and residents of the developing world. Very little is known about the biology of the organism, the(More)
Orally administered bovine immunoglobulins with specific activity against colonization factors of enterotoxigenic Escherichia coli (ETEC) could provide passive protection against ETEC challenge in volunteers. Twenty healthy adult volunteers ingested either a placebo or a partially enteric-coated preparation of bovine immunoglobulins with activity against(More)
Bovine hyperimmune anti-Cryptosporidium colostrum immunoglobulin (BACI) decreases the intensity of Cryptosporidium parvum infection in vitro. We investigated the prophylactic effect of BACI in healthy adults challenged with C. parvum. After we established an oocyst dose that resulted in 100% infection in four volunteers (baseline group), 16 volunteers were(More)
The type III polysaccharides of group B Streptococcus in its native state chemically consists of glucose, galactose, glucosamine, and sialic acid. The core of this polysaccharide lacks sialic acid and precipitates with type III antiserum to give a partial identity with the precipitate between the native antigen and this serum. The core determinant is(More)
The Ca2+-stimulated release of vesicle contents from cortical fragments prepared from sea urchin eggs is an in vitro model for exocytosis. Cortical fragments have been isolated either in suspension (cell surface complex, CSC preparation), or attached to polycation-coated surfaces (cortical lawn, CL preparation). CL, but not CSC, have been reported to(More)
Passive antibody immunotherapy (PAI) for cryptosporidiosis is a treatment strategy that has been actively pursued in laboratory studies and early-stage clinical studies for the last decade. Several experimental approaches have been initiated, including use of bovine colostrum and colostral antibodies (hyperimmune and natural), monoclonal antibodies, chicken(More)
Experimental animal model systems have been used by many investigators to explore the pathogenicity of obligate anaerobes. During the last 15 years, research in our laboratory has utilized an experimental model for intraabdominal sepsis to define the contribution of obligate anaerobes to the infectious process. These studies have shown that obligate(More)